Most research into the microbiome has focused on the trillions of bugs that live in our guts. But our skin is also home to multiple microbial ecosystems. The community that lives in your armpit could look quite different from the community that lives on your eyelids. We are still figuring out exactly what these microbes are doing, but they seem to feed on our secretions, possibly produce some beneficial secretions of their own, and protect us from infections.
They also appear to influence the way our immune systems work. A growing body of research suggests that microbes living in and on our bodies can amplify or turn down the immune response to something that might potentially cause us harm—whether it’s an infection, a tumor, or something more benign.
Simply introducing a microbe to the skin of an animal can also trigger an immune response—albeit one that doesn’t cause all the usual signs of an infection, like pain, fever, or sickness. This is somewhat surprising, says Michael Fischbach at Stanford University, because these microbes don’t tend to be harmful: “They’re our friends.” Adding a microbe to the skin of a mouse, for example, can have an effect similar to giving the same mouse a vaccination, he says.
Fischbach and his colleagues wondered if they might be able to hijack this effect to tweak the immune response.
The team started the investigation by choosing a microbe that is commonly found on human skin. S. epidermidis is thought to be a member of the human microbiome, and it doesn’t typically cause disease. The microbes the researchers used were originally collected from behind the ear of a human volunteer, says Fischbach.
The researchers modified these microbes by inserting a new gene into them. The gene codes for a protein that sits on the surface of some cancer cells. The idea is that if the immune system generates cells that recognize the microbe, these cells will also recognize tumors.
The team then applied these “designer bugs” to mice by wiping them over the heads of the animals with a cotton bud. Another group of mice had regular, unmodified samples of the bacteria smeared onto them. In both cases, the microbes quickly made a home for themselves on the mice’s skin, says Fischbach.
At the same time, the mice were injected with skin cancer cells. These cells were taken from other mice that had cancer, so they had the target protein on their surface.
The Download: child online safety laws, and ClimateTech is coming
Matt Kaeberlein is what you might call a dog person. He has grown up with dogs and describes his German shepherd, Dobby, as “really special.” But Dobby is 14 years old—around 98 in dog years.
Kaeberlein is co-director of the Dog Aging Project, an ambitious research effort to track the aging process of tens of thousands of companion dogs across the US. He is one of a handful of scientists on a mission to improve, delay, and possibly reverse that process to help them live longer, healthier lives.
And dogs are just the beginning. One day, this research could help to prolong the lives of humans. Read the full story.
We can still have nice things
A place for comfort, fun and distraction in these weird times. (Got any ideas? Drop me a line or tweet ’em at me.)
+ All hail the unsung women of indie sleaze.
+ It’s officially October!
+ This list of sartorial advice has been entertaining us at MIT Technology Review—how many points do you agree with?
+ Put down the expired milk, it’s got a whole lot more to give. 🥛
+ Some top tips for remembering your dreams more fully: should you want to, that is.
Everything you need to know about artificial wombs
The technology would likely be used first on infants born at 22 or 23 weeks who don’t have many other options. “You don’t want to put an infant on this device who would otherwise do well with conventional therapy,” Mychaliska says. At 22 weeks gestation, babies are tiny, often weighing less than a pound. And their lungs are still developing. When researchers looked at babies born between 2013 and 2018, survival among those who were resuscitated at 22 weeks was 30%. That number rose to nearly 56% at 23 weeks. And babies born at that stage who do survive have an increased risk of neurodevelopmental problems, cerebral palsy, mobility problems, hearing impairments, and other disabilities.
Selecting the right participants will be tricky. Some experts argue that gestational age shouldn’t be the only criteria. One complicating factor is that prognosis varies widely from center to center, and it’s improving as hospitals learn how best to treat these preemies. At the University of Iowa Stead Family Children’s Hospital, for example, survival rates are much higher than average: 64% for babies born at 22 weeks. They’ve even managed to keep a handful of infants born at 21 weeks alive. “These babies are not a hopeless case. They very much can survive. They very much can thrive if you are managing them appropriately,” says Brady Thomas, a neonatologist at Stead. “Are you really going to make that much of a bigger impact by adding in this technology, and what risks might exist to those patients as you’re starting to trial it?”
Prognosis also varies widely from baby to baby depending on a variety of factors. “The girls do better than the boys. The bigger ones do better than the smaller ones,” says Mark Mercurio, a neonatologist and pediatric bioethicist at the Yale School of Medicine. So “how bad does the prognosis with current therapy need to be to justify use of an artificial womb?” That’s a question Mercurio would like to see answered.
What are the risks?
One ever-present concern in the tiniest babies is brain bleeds. “That’s due to a number of factors—a combination of their brain immaturity, and in part associated with the treatment that we provide,” Mychaliska says. Babies in an artificial womb would need to be on a blood thinner to prevent clots from forming where the tubes enter the body. “I believe that places a premature infant at very high risk for brain bleeding,” he says.
And it’s not just about the baby. To be eligible for EXTEND, infants must be delivered via cesarean section, which puts the pregnant person at higher risk for infection and bleeding. Delivery via a C-section can also have an impact on future pregnancies.
So if it works, could babies be grown entirely outside the womb?
Not anytime soon. Maybe not ever. In a paper published in 2022, Flake and his colleagues called this scenario “a technically and developmentally naive, yet sensationally speculative, pipe dream.” The problem is twofold. First, fetal development is a carefully choreographed process that relies on chemical communication between the pregnant parent’s body and the fetus. Even if researchers understood all the factors that contribute to fetal development—and they don’t—there’s no guarantee they could recreate those conditions.
The second issue is size. The artificial womb systems being developed require doctors to insert a small tube into the infant’s umbilical cord to deliver oxygenated blood. The smaller the umbilical cord, the more difficult this becomes.
What are the ethical concerns?
In the near term, there are concerns about how to ensure that researchers are obtaining proper informed consent from parents who may be desperate to save their babies. “This is an issue that comes up with lots of last-chance therapies,” says Vardit Ravitsky, a bioethicist and president of the Hastings Center, a bioethics research institute.
The Download: brain bandwidth, and artificial wombs
Last week, Elon Musk made the bold assertion that sticking electrodes in people’s heads is going to lead to a huge increase in the rate of data transfer out of, and into, human brains.
The occasion of Musk’s post was the announcement by Neuralink, his brain-computer interface company, that it was officially seeking the first volunteer to receive an implant that contains more than twice the number of electrodes than previous versions to collect more data from more nerve cells.
The entrepreneur mentioned a long-term goal of vastly increasing “bandwidth” between people, or people and machines, by a factor of 1,000 or more. But what does he mean, and is it even possible? Read the full story.
This story is from The Checkup, MIT Technology Review’s weekly biotech newsletter. Sign up to receive it in your inbox every Thursday.
Everything you need to know about artificial wombs
Earlier this month, US Food and Drug Administration advisors met to discuss how to move research on artificial wombs from animals into humans.
These medical devices are designed to give extremely premature infants a bit more time to develop in a womb-like environment before entering the outside world. They have been tested with hundreds of lambs (and some piglets), but animal models can’t fully predict how the technology will work for humans.